Determination of the Limit of Detection of Multiple Pesticides Utilizing Gold Nanoparticles and Surface-Enhanced Raman Spectroscopy.

Exposure to commonly used pesticides poses significant health risks to humans and wildlife. Hence, accurate and sensitive pesticide residue testing methods are imperative to minimize potential health hazards. In this study, we report a method to detect several pesticide residues at trace levels utilizing colloidal gold nanoparticles and surface-enhanced Raman spectroscopy (SERS). Gold nanoparticles suspended in water have been found to enhance Raman scattering from 21 pesticides, including fungicides and insecticides, such as neonicotinoids and organothiophosphates. Measured limits of detection ranged from 0.001 to 10 parts per million (ppm). Furthermore, simultaneous detection of two pesticides, phosmet and thiram, in both a mixture solution and on apple skin, was performed using the SERS method and principal component analysis. The results presented here indicate that SERS coupled with colloidal gold nanoparticles is a potential useful tool for identifying pesticides at trace levels for food safety applications.